The starter circuit shown in the figure was found in an old European documentation. The circuit makes use of an SCR which is still common and the diac can be of any type.
This transistor tester with different gain ranges was found in documentation from the 1980s. The...
This Japanese radio from the 60's has an output power of 200mW and is powered by a voltage of 9 V....
This circuit uses an unusual component today which is the integrated circuit. We found this...